Stem functions

Primary EducationGrade 3ScienceCV-PRI-G03-SCI-U02-L0345–60 min
Learning LabPractise with explanations. Revise with flashcards. Review what needs more work.

You will learn

  • Say what stems do.
  • Explain how water moves in a stem.
  • Compare soft and woody stems.
  • Link stems to plant size.

Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.

Student lesson

The lesson in 60 seconds

  1. Stems support the plant.
  2. Stems transport water and food.
  3. Some stems are soft and some are woody.
  4. Stems connect roots and leaves.

Words to know

support
to hold up
transport
to carry from place to place
woody
hard like wood
herb
a plant with a soft stem

1. Discover: The tall tree and the small herb

Nana sits beside a tall tree with a thick brown stem called a trunk. Next to it a small basil plant has a soft green stem. “Both stems carry water,” her teacher says. “The trunk is also strong enough to hold a huge tree.”

Think: Why does a tree need a strong stem?

2. Understand: Stems

Idea 1: Support

The stem supports leaves and flowers so they can reach light. Strong stems hold big plants up.

Idea 2: Transport

Tiny tubes in the stem transport water up from the roots and food down from the leaves.

Idea 3: Types of stems

A herb has a soft green stem. A shrub has several woody stems. A tree has one thick woody trunk.

Remember: Stems support plants and transport water and food. Stems can be soft or woody.

3. Worked examples

Example 1 (I show you): Job

Leaves reach light.

  1. Stem holds up.
  2. Support.
  3. Job found.

Answer: Stems support leaves.

Example 2 (We do it together): Transport

Water to the leaf.

  1. Goes up the stem.
  2. Tubes carry it.
  3. Transport.

Answer: Stems transport water.

Example 3 (You try): Type

Tree trunk.

Show the steps and answer
  1. Hard.
  2. Woody.
  3. Strong.

Answer: A trunk is woody.

Did you know?

Bamboo is a grass with a hollow stem and can grow nearly a metre in a day.

Why this matters

Stems let plants grow tall and move water and food.

4. Explore: Stems at work

Show water rising in a white flower stem.

  1. Place a white flower in coloured water.
  2. Wait a day.
  3. Look at the petals.
  4. Explain.
Think about it: what did you notice?

What did you notice? Petals took the colour, so water travelled up the stem.

Safety first: Use only food colouring and water. Wash hands after handling plants. Do not taste flowers.

5. Practise

Say it in a sentence

Use these starters when you talk about the lesson. Say them out loud.

  • Stems ___ the plant.
  • Stems ___ water.
  • A tree has a ___ trunk.
  • A soft stem is on a ___.

Guided practice

Question 1. What do stems do?

Support and transport.

Question 2. What is a herb?

A soft-stemmed plant.

Question 3. What is a woody stem?

A hard stem.

Independent practice

Level 1: Start

  1. What do stems do?
  2. What is a herb?
  3. What is a woody stem?
  4. What carries water?
  5. What connects roots and leaves?

Level 2: Grow

  1. Why do tall trees need strong stems?
  2. Why do leaves need the stem?
  3. Why does the petal change colour?

Level 3: Stretch

  1. Sort stems soft or woody.
  2. Explain the flower test.
  3. Draw a stem with tubes.

Answers are in the answer key below. Try first, then check.

6. Apply: Science in everyday life

Name a plant with a woody stem.

Show a sample answer

Mango tree.

Another one. Tell a family member one thing from this lesson. Use the words you learned.

Show a sample answer

A clear sentence that uses at least one word from Words to know.

7. Common mistakes

Mistake: “Stems are only for holding.”
Fix: They also transport.
Another mistake: “All stems are hard.”
Fix: Some are soft.

8. Lesson summary and revision card

I can…

  • I can say what stems do.
  • I can explain how water moves in a stem.
  • I can compare soft and woody stems.
  • I can link stems to plant size.

9. Check and master

Answer all 14 questions. You will see feedback after each one.

1. Stems … plants

2. Stems transport …

3. A tree trunk is …

4. A herb has a … stem

5. Stems connect roots and …

6. Coloured water reaches the …

7. We use only … colouring

8. We do not taste …

9. We wash hands after …

10. Bamboo has a … stem

11. A shrub has several … stems

12. Stems help leaves reach …

Challenge 1. Water in coloured petals shows the stem …

Challenge 2. Which stem is strongest?

Your result appears here after you answer every question.

10. Key takeaways

  • Stems support the plant.
  • Stems transport water and food.
  • Some stems are soft and some are woody.
  • Stems connect roots and leaves.

11. Next lesson

Next lesson: Leaf functions. Keep going with the next idea in this course.

Exam practice

These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.

  1. Give two jobs of stems. [2 marks]
  2. Compare herb and tree stems. [2 marks]
  3. Explain the flower test. [3 marks]
  4. What do tubes carry? [2 marks]
  5. Safety rule? [1 mark]

Total: 10 marks.

Marking guide and model answers
  1. Support [1]; transport [1]
  2. Soft [1]; woody [1]
  3. Coloured water [1]; petals change [1]; water moves up stem [1]
  4. Water [1]; food [1]
  5. Any [1]

Score guide: 9 to 10 = secure. 6 to 8 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.

Printable worksheet

  1. What do stems do?
  2. What is a herb?
  3. What is a woody stem?
  4. What carries water?
  5. What connects roots and leaves?
  6. Why do tall trees need strong stems?
  7. Why do leaves need the stem?
  8. Why does the petal change colour?
  9. Sort stems soft or woody.
  10. Explain the flower test.

Homework

Find three stems at home and sort them as soft or woody.

Answer key and marking scheme

Question Expected response Marks
1. What do stems do? Support and transport. 1
2. What is a herb? A soft-stemmed plant. 1
3. What is a woody stem? A hard stem. 1
4. What carries water? Tubes in the stem. 1
5. What connects roots and leaves? The stem. 1
6. Why do tall trees need strong stems? To hold weight. 1
7. Why do leaves need the stem? To reach light. 1
8. Why does the petal change colour? Water moved up. 1
9. Sort stems soft or woody. Table. 1
10. Explain the flower test. Paragraph. 1
Total 10

Independent practice answers. Level 1: 1 Support and transport.; 2 A soft-stemmed plant.; 3 A hard stem.; 4 Tubes in the stem.; 5 The stem.. Level 2: 1 To hold weight.; 2 To reach light.; 3 Water moved up.. Level 3: 1 Table.; 2 Paragraph.; 3 Diagram..

Quiz answers: 1 B, 2 C, 3 A, 4 B, 5 C, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 B, Challenge 2 C.

Mastery and remediation

Objective Bronze (Developing) Silver (Proficient) Gold (Advanced)
O1 Say what stems do Shows this with help from an adult or a picture Does this independently and explains how they know Explains it clearly and uses it in a new situation
O2 Explain how water moves in a stem Shows this with help from an adult or a picture Does this independently and explains how they know Explains it clearly and uses it in a new situation
O3 Compare soft and woody stems Shows this with help from an adult or a picture Does this independently and explains how they know Explains it clearly and uses it in a new situation
O4 Link stems to plant size Shows this with help from an adult or a picture Does this independently and explains how they know Explains it clearly and uses it in a new situation

Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.

If a learner struggles

  1. Find the misconception: “Stems are only for holding.” They also transport.
  2. Explain another way: use real objects, pictures or actions first, then words.
  3. Show a simpler example: Explain stem jobs and types.
  4. Guided practice: work through one example together and let the learner try the next one.
  5. Reassess: use the quiz again or the worksheet.
  6. Move on when the learner shows Silver-level evidence independently.

For parents and guardians

In this lesson your child learns what stems do. You do not need to be an expert to help.

  • Look at stems on a walk.
  • Ask, “Soft or woody?”
  • Wash hands after handling plants.
  • Ask “how do you know?” after each answer, and listen.
  • Praise effort, not only right answers. Mistakes are how we learn.
  • Ten to fifteen minutes a day is better than one long session.

Teacher package

1–5. Objectives, prerequisites, materials, preparation, duration

Lesson objectives. Learners will: say what stems do; explain how water moves in a stem; compare soft and woody stems; link stems to plant size.

Prerequisite knowledge. Grade 2 plant ideas: the parts of a plant, what seeds need to grow, and the plant life cycle.

Materials. White flowers, cups, water, food colouring. Low-resource options: use chalk or charcoal on a board or wall, drawings in the sand, and objects from the classroom instead of printed materials.

Preparation. Start the flower test a day before.

Suggested duration. 45–60 minutes. It can be split into two shorter sessions.

6–9. Teaching procedure, explanation notes, guided and independent activities

Introduction (5 min). Show a tree branch and a herb and ask, “How do the stems differ?”

Explanation (10 min). Teach stem jobs.

Guided activity (10 min). Learners run the flower test.

Independent activity (10 min). Share results.

Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.

Key questions. What do stems do? Soft or woody?

Teacher explanation notes. Start with real objects and safe, hands-on observation. Then talk about what was seen, then draw and write. Always say “how do you know?”. Keep to the safety notes, and use local, safe materials.

10–12. Differentiation, formative assessment, common misconceptions

Support. Use real objects and pictures, short sentences and a partner. Let learners point, show or draw instead of writing. Extension. Ask learners to find a new example at home and explain how they know.

Formative assessment. Listen to learners read and explain, ask “how do you know?”, and check the independent work.

Misconceptions. “Stems are only for holding.” They also transport.

13–15. Assessment questions, answer keys, marking scheme

Use the quiz, the 10-mark exam practice and the worksheet on this page. All answers and marking guides are in the answer sections above. Re-check every answer before use.

16–19. Remediation, enrichment, homework, teacher reflection

Remediation. Explain stem jobs and types. Enrichment. Look for one new example near your home or school, draw it and explain it to someone. Homework. See above.

Teacher reflection. After teaching, record: which ideas learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.

Sources and standards

This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points: Next Generation Science Standards, Cambridge Primary Science and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.

Research used to shape this lesson. Courseversity Science curriculum, Grade 3 Unit 2, topic 3; Next Generation Science Standards, structure and function and life cycles of plants; Cambridge Primary Science Stage 3, plants and humans; IB Primary Years Programme, how the world works. These sources informed the lesson.

Learning Lab

14 questions in 3 rounds · 4 flashcards · targeted review. Log in to save your progress.

Learning LabPractise with explanations. Revise with flashcards. Review what needs more work.
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